Detailed Explanation of Key Points for High-Yield Cultivation Techniques of Yujin

Yujin, also known as Huang Yujin, Lü Yujin, Gui Yujin, etc. Its underground tubers are used medicinally, with effects of relieving depression, promoting qi flow, relieving pain, resolving blood stasis, and promoting bile secretion. It mainly treats distending pain in the chest and hypochondrium, jaundice, dysmenorrhea, epilepsy, etc.

Morphological Characteristics

1. Wenyujin (Curcuma wenyujin), a perennial rosette herb of the Zingiberaceae family, with a thickened rhizome; the cross-section center is lemon yellow, the outer part is nearly white, with a slight aroma, and the ends are swollen into a spindle shape. The leaves are broadly elliptical, 30-75 cm long and 14-22 cm wide, with acuminate or short caudate tips, glabrous, and the base is cuneate and extends down to the petiole. The flowering stem emerges from the stem base before the leaves, and the spike is rounded; the bracts in the middle and lower parts are broadly ovate and pale green. The calyx is white with 3 toothed lobes; the corolla is white, funnel-shaped, with rough hairs near the apex; there is 1 fertile stamen, pale yellow; the ovary is inferior.

2. Jianghuang (Curcuma longa), a perennial herb, with a thick rhizome; the main rhizome is ovate, the lateral rhizomes are finger-shaped and red-yellow; the leaves are narrowly elliptical, 20-30 cm long and 5-15 cm wide, glabrous on both sides; the inflorescence emerges from within the leaf sheaths. The spike is cylindrical; the bracts are ovate to nearly circular, green-white, with several flowers in the axils; the calyx is green-white with 3 teeth; the corolla tube is 1.5 cm long, with 3 lobes, pale yellow, the upper one larger; the lateral staminodes are petal-like and yellow, the labellum is nearly circular and yellow-white, and there is 1 fertile stamen, connate with the staminodes; the anther is oblong and spurred at the base. The ovary is inferior.

3. Guangxi Ezhu (Curcuma kwangsiensis), a perennial herb, 80-110 cm tall. The tuberous roots are spindle-shaped; the main rhizome is ovate-circular to ovate, and the lateral rhizomes are finger-shaped. Fleshy, the cross-section is white or slightly yellow; the leaves are long elliptical, densely covered with coarse soft hairs on both sides; the spike is cylindrical and emerges from the rhizome before the leaves; the bracts in the upper tuft are mid-elliptical to ovate-elliptical, pink to pale red; the middle and lower bracts are ovate-circular and green-white; the calyx tube is white with 3 teeth at the apex; the corolla is pink, the lateral staminodes are petal-like and pale yellow, and the ovary is inferior.

4. Peng'ezhu (Curcuma phaeocaulis), a perennial herb, with a lumpy rhizome and cylindrical lateral rhizomes, pale yellow. The roots are slender and swollen at the ends; the leaves are elliptical. The inflorescence emerges from the rhizome, the spike is broadly elliptical, and the corolla has 3 lobes. The lateral staminodes are smaller than the labellum, and the labellum is nearly laterally ovate.

I. Growth Habits: Yujin prefers a warm and humid environment. It is afraid of drought, afraid of waterlogging, and not cold-tolerant. Soil requirements: loose and fertile topsoil, hard subsoil, or sandy loam is best. Saline-alkali land and low-lying land are not suitable for planting. Continuous cropping is avoided.

II. Land Preparation and Fertilization: Select suitable field plots and carry out intensive cultivation. Combined with land preparation, apply sufficient base fertilizer: 5000 kg of farmyard manure per mu, 50 kg of cake fertilizer, 20 kg of urea, and 50 kg of phosphate and potassium fertilizer. Then make high beds 60 cm wide, with a 15 cm ditch between beds to facilitate watering and drainage. Wait for sowing.

III. Sowing: Yujin is propagated by tubers. The sowing period is spring sowing, around Qingming. When harvesting Yujin, select rhizomes that grow robustly and are free of pests and diseases to store as seed. Before planting, take them out and sun-dry for 1—2 days, remove the fibrous roots, separate them by size, and the large ones can be cut lengthwise into several pieces, each with 1—2 buds. Let them cool slightly so the wounds heal, then plant them in the prepared beds at a row spacing of 30×20 cm. Cover with soil, water to preserve moisture, and promote survival. The sowing rate is 80 kg per mu.

IV. Field Management: After Yujin seedlings emerge evenly, pay attention to intertillage and weeding. Water during dry weather, and drain promptly during rainy weather. Around the Beginning of Autumn, when the rhizomes enter the expansion stage, topdress once: apply 2000 kg of human feces and urine per mu, 10 kg of urea, and 10 kg of potassium dihydrogen phosphate.

V. Pest and Disease Control: Yujin has relatively few pests and diseases; if found, control them by conventional methods. For underground pests, phoxim can be used to prepare poison bait for trapping and killing.

VI. Harvesting and Processing: Yujin is generally harvested after autumn, after the aboveground stems and leaves wither. Remove the soil from the dug-out underground tubers of Yujin, put them into boiling water and boil for 15 minutes; after boiling thoroughly, take them out and sun-dry them, and they can be sold as medicine. The yield is 300 kg per mu. After removing Yujin, the remaining rhizomes, except those kept for seed, are washed clean of soil, boiled or steamed thoroughly, then sun-dried or oven-dried, and the fibrous hairs and coarse skin are rubbed off to obtain Ezhu. The yield is 100 kg per mu.